Measurement and Modeling of Local Scale Energy and Mass Exchanges in Urban Environments

Indiana University, Bloomington IN

Investigators

Abstract

Land surface and atmospheric alteration by urbanization leads to the development of distinct urban climates, which ultimately due to differences in the budgets of heat, mass, and momentum between the city and its pre-existing landscape. This study, through measurements and simple modeling, will enhance current understanding of surface - atmosphere exchanges in cities and their spatial variability at the local or neighborhood scale. This work will be conducted in two inter-related parts. First, a multi-city urban hydro-meteorological database consisting of surface energy balance fluxes, standard meteorological variables, and detailed spatial information on surface cover (materials and morphology) will be developed. This will be achieved by integrating results from previous studies, published and unpublished, and by conducting new long-term flux measurements at three carefully selected sites (Baltimore, USA; Lodz, Poland; Marseille, France). Second, simple parameterization schemes to simulate each of the surface energy balance fluxes in urban areas will be developed and evaluated. The objective is to develop a scheme with broad utility, thus it will be based on routinely collected meteorological data and simple surface parameters. Schemes for the individual fluxes will be evaluated separately and then integrated into a model called Local-scale Urban Meteorological Parameterization Scheme (LUMPS). The new data compiled and measured will be used to independently evaluate LUMPS. Urban areas represent a location where a large and ever-increasing proportion of the world's population live, and where a disproportionate share of natural resources are used. The data collected in this study will enhance current understanding of the fundamental physical processes involved in the generation of urban climates and their spatial variability. The integrated model developed from this research (LUMPS) will be capable of simulating the spatial variability of energy balance fluxes within and between cities. Given the easily-available data inputs of LUMPS (standard meteorological data and surface characteristics), it promises to be a tool of practical utility for the broad group of scientists interested in understanding, predicting, and mitigating urban climates.